Percentage of losses against the eventual winner in GS (out of all the player's loss in GS) for some of the greatest players of the last 10 years. You can add some other and former player's percentage if you want.

Genie's 3 losses happened at three slams in a row from AO 2014 to Wimbledon 2014! That's quite unusual, I guess. But the probability of losing to the eventual winner is of course higher when you're going deep at every tournament, as Bouchard did at those three slams (I'm stating the obvious, I know).

Do you have any stats of number of losses to the eventual winner in R1 in the grand slams? (like when Schiavone lost to Serena in R1 at US Open 2013).

Sharon Walsh (lost R1 to Evert at the 1977 USO and R1 to Goolagong at the 1980 Wimbledon)
Sandra Kleinova (lost R1 to Iva Majoli at the 1997 FO and R1 to Jana Novotna at the 1998 Wimbledon)
Kimberly Po (lost R1 to Steffi Graf at the 1994 AO and R1 to Serena Williams at the 1999 USO)
Emilie Loit (lost R1 to Jennifer Capriati at the 2001 FO and R1 to Serena Williams at the 2003 AO)
Sofia Arvidsson (lost R1 to Ana Ivanovic at the 2008 FO and R1 to Samantha Stosur at the 2011 USO)
Barbora Zahlavova-Strycova (lost R1 to Na Li at the 2011 FO and R1 to Serena Williams at the 2012 W)